The future of computing may be gestating - not in computer labs, but in an obscure discipline called process control, where scientists have discovered that a little smear of rat brain can solve one of the big problems in chemical engineering.

Despite the enormous progress made in the electronic digital computer,
the box on your desk - or on your lap, or in your pocket - is the same
sort of machine as the 50-year-old room-sized monster. It manipulates
binary code the way it has been programmed to do. Computers of this
type will become faster and more powerful for a time, but there are
already signs they are approaching limits in both hardware and
software. Even without these limits, digital computers of any
conceivable power will have difficulty accomplishing seemingly simple
tasks. A big machine capable of running a space mission fails
completely when asked to pick a face from a crowd or to drive a robot
across a room full of obstacles. These sorts of problems have already
been solved in nature, in an infinite variety of ways, by the
associations of neurons directing living creatures. The next big jump
in computing, potentially as important as the jump that created the
programmable electronic computer, must be inspired by biology.

If the past is any guide, this will probably not occur in the likely
places - the major hardware or software companies. The original
electronic computer was hatched not by the big electronic firms of the
time nor by the banking or insurance businesses that first profited
from its development, but in an obscure corner of the
military-industrial complex, by a group with lots of money and an
urgent need to solve artillery trajectories. It may be that the
successor to that type of machine is gestating far from the hotbeds of
computerdom, in an obscure corner of the chemical business: a field
called process control.

A modern chemical plant is among the most complex of structures,
involving acres of pipes, tanks, reactor vessels, distillation
columns, valves, and compressors. In this it compares to other complex
artifacts, such as telecom nets, computers, and power grids. The
difference is that these others are susceptible to what systems people
call linear control: turn the volume knob on your stereo, and you go
smoothly from barely audible to ear-splitting. Electronics is like
that, and though there are nonlinearities in electronics, engineers
are clever enough to compensate for them and render them nearly
worthless. But at the heart of every chemical plant are reactor
vessels and distillation columns; reactions take place there that are
nowhere near linear. Not only are chemical reactions nonlinear, but
they are dynamically nonlinear: changes in heat and pressure have
hard-to-control effects on outputs of usable stuff; plus, each batch
has a kind of memory.

Most of us have had domestic experience with such reactions. Consider
the omelet. You start with an inedible mix of protein and fat. You add
heat and air to this mix in precise amounts. At a certain moment the
last increment of heat and air, indistinguishable from those that have
proceeded it, produces a perfect omelet. That's nonlinearity. The
dynamism is seen in the omelet's memory. If you let it go beyond the
perfect point, there's no way to bring it back to perfection by, say,
cooling it. You have to throw it away and start over. Although
chemical engineering has been a science for a century or so now, it is
still a lot more like cooking omelets than the people who run chemical
companies would like. As in a kitchen, yum can turn to yuck in an
instant, and the difference between the two makes up a large part of
the bottom line. This is where process control comes in.

There is another difference that chemical people don't talk about
much. When something goes sour on a telecom net or a power grid,
people get pissed off and can lose significant amounts of money. When
a chemical plant goes sour, you get The Fireball: large pieces of
white-hot metal go flying everywhere at high speeds, and you can lose
a hundred-million-dollar investment in four seconds. That's if you're
lucky. If you're unlucky, you get Bhopal.

Chemical companies compensate for these characteristics in the same
way chefs do - by carefully watching the pot, using a technology that
could be described as A Lot of Old People Who Know How to Make Teflon
Without Wiping Out Wilmington. This is expensive, and wasteful, and
often leaky. Meanwhile, big chemical concerns are under increasing
economic pressure, stemming from shrinking profit margins on standard
chemicals, from the need to make more of their income from ever more
complex processes, from the expiration of their patents, and from
environmental demands to reduce leaks and waste products. This has set
the stage for a new look at process
control.

Michael Gruber( mag@well.com), a former biologist and former civil servant, writes in Seattle using someone else's name.